1. Field of the Invention
The present invention relates to a hydraulic hammer having buffer assembly, and more particularly, to a hydraulic hammer for reducing stress having an improved structure in which repeated tensile banding stress applied to the hammer assembly can be reduced.
2. Description of the Related Art
In general, a hydraulic hammer includes a housing assembly and a hammer assembly, in which a piston installed in a hammer assembly rises and falls by controlling the high pressure fluid of a hydraulic pump supplied to a hammer assembly to forcibly move a tool, which crushes boulders or concrete by forceful impact of the tool. The hammer assembly is installed in the housing assembly, which is mounted on apparatuses such as an excavator or a loader.
Referring to FIG. 1, a housing assembly includes a housing 210, a top cover plate 220, a top buffer 250, an upper wearing plate 240 and a lower wearing plate 230, and a hammer assembly includes an accumulator 110, a valve housing 120, a cylinder 130, a front head 140 and a side rod 131.
The upper wearing plate 240 and the lower wearing plate 230 support the front head 140 of the hammer assembly to suppress horizontal movement, and the top buffer 250 supports the hammer assembly to suppress movement against the tool and absorb impacts of the hammer assembly.
The upper wearing plate 240 and the lower wearing plate 230 formed of urethane or plastic may be deformed. Thus, when external force is applied, the hammer assembly in the housing assembly rotates around the front head 140. Here, when the upper portion of the hammer assembly does not rotate, fatigue due to tensile banding stress accumulates on the side rod 131 of the hammer assembly.
The conventional top plate 220 is typically formed of a steel plate and the top buffer 250 is formed of urethane, so that the top plate 220 and the top buffer 250 do not easily slide. Thus, repeated tensile banding stress is applied to the hammer assembly during operation, which causes failure of the side rod 131.